A single frequency network (SFN) is a broadcast network in which several transmitters simultaneously transmit the same signal over the same frequency channel. One type of conventional SFN is known as a hybrid satellite-terrestrial SFN. An example hybrid SFN is defined in the Digital Video Broadcasting (DVB) standard “Framing Structure, channel coding and modulation for Satellite Services to Handheld devices (SH) below 3 GHz,” ETSI EN 302 583 V1.1.2 (February 2010).
In these types of networks, the terrestrial transmitter usually needs certain information that is contained in the satellite signal in order for the terrestrial transmitter to generate and transmit the terrestrial signal properly.
In a conventional hybrid satellite-terrestrial network, such as a Digital Video Broadcasting Satellite Services to Handheld devices (DVB-SH) SFN, if the satellite signal and terrestrial signal are transmitted in identical (or alternatively adjacent) frequency bands, then required satellite information cannot be recovered from the satellite signal using a receiving antenna situated relatively close to the location of the terrestrial transmitter due to radio-frequency (RF) interference caused by the terrestrial transmitter. Consequently, at the site of a terrestrial transmitter, the satellite signal is often too weak relative to the signal from the terrestrial transmitter to be decoded for recovery of the required satellite information directly from the over-the-air (OTA) signal received on site. Because of this, the required information about the satellite signal is obtained at a location remote to the terrestrial transmitter, and transmitted to the site of the terrestrial transmitter via some other network. This other network is sometimes referred to as an “auxiliary” network. However, auxiliary networks such as these can be relatively expensive and/or inaccurate.